Coated laundry and/or automatic dishwashing tablets having a chamfered edge for improved structural integrity

ABSTRACT

A laundry and/or automatic dishwashing tablet including a core ( 10 ) formed by compressing a particulate material, wherein the particulate material includes a detersive surfactant and a builder. The core ( 10 ) is compressed into a tubular configuration having a polygonal cross section and a plurality of surfaces meeting to form a plurality of edges, thereby forming a contoured core ( 10 ), wherein at least one of the plurality of edges is chamfered ( 20 ). The non-particulate detergent product further includes a coating ( 12 ) which substantially covers the contoured core ( 10 ).

This application claims the benefit of provisional application60/083,257 filed Apr. 27, 1998.

TECHNICAL FIELD

The present invention relates to detergent compositions innon-particulate form that have a protective coating. More particularly,the invention relates to coated non-particulate detergent products e.g.,tablet, block or bar, having a specially contoured surface which reducesthe coating's susceptibility to being chipped or broken away duringmanufacture, storage and handling.

BACKGROUND OF THE INVENTION

Non-particulate detergents are an attractive alternative to granular orparticulate forms of detergents from the standpoint of simplifying thedosing of such detergents for automatic laundry or dishwashing machines.Non-particulate detergents are usually supplied in the form of bars,tablets or briquettes and they not only prevent spillage of thedetergent composition but also eliminate the need for the consumer toestimate the correct dosage of the detergent composition per wash.Non-particulate detergents minimize the contact by the consumer with thedetergent.

In order to improve the hardness of a non-particulate detergent, such asa tablet, the tablets are occasionally encapsulated by a protectivecoating, which is broken when the tablet is immersed in water in thewashing machine, thereby exposing the soft core which breaks up easilyand rapidly, releasing the active ingredients into the wash solution.However, one problem frequently encountered with coated detergenttablets is that during manufacture, transportation, storage andhandling, the coating can get chipped or broken away, especially aroundsharp edges or corners, by either rubbing against each other or againstanother surface. This not only reduces the structural integrity of thedetergent tablet but also takes away from its appearance and aesthetics.Most consumers do not like to purchase a detergent tablet product whichis chipped or has broken edges.

It is thus highly desirable to have a coated detergent tablet producthaving a surface configuration which reduce the coating's susceptibilityto chipping and fracture so that the coating remains adhered to thetablet during packaging, transport, storage and handling prior toeventual use.

BACKGROUND ART

The prior art is replete with methods of forming and coating tablets.

GB-A-0 989 683, published on Apr. 22, 1965, discloses a process forpreparing a particulate detergent from surfactants and inorganic salts;spraying on water-soluble silicate; and pressing the detergent particlesinto a solid form-retaining tablet. Finally a readily water-solubleorganic film-forming polymer (for example, polyvinyl alcohol) provides acoating to make the detergent tablet resistant to abrasion andaccidental breakage.

EP-A-0 002 293, published on Jun. 13, 1979, discloses a tablet coatingcomprising hydrated salt such as acetate, metaborate, orthophosphate,tartrate, and sulphate.

EP-A-0 716 144, published on Jun. 12, 1996, also discloses laundrydetergent tablets with water-soluble coatings which may be organicpolymers including acrylic/maleic co-polymer, polyethylene glycol,PVPVA, and sugar.

SUMMARY OF THE INVENTION

The invention meets the needs above by providing a non-particulatedetergent product including, a core formed by compressing a particulatematerial comprising a detersive surfactant and a builder. The core iscompressed into a tubular configuration having a polygonal cross-sectionand a plurality of surfaces meeting to form a plurality of edges,thereby forming a contoured core, wherein at least one of the pluralityof edges is chamfered. The non-particulate detergent product furtherincludes a coating which substantially covers the contoured core.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a portion of the detergent core,showing the details of a chamfer according to one embodiment of thepresent invention;

FIG. 2 shows a cross-sectional view of a portion of the detergent core,showing the details of a plurality of chamfers according to anotherembodiment of the present invention; and

FIG. 3 shows a cross-sectional view of a portion of the detergent core,showing the details of a radiused chamfer according to yet anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the preferred embodiment of the present invention, a core is formedby compressing a particulate material comprising a detersive surfactantand a builder.

The Particulate Detergent Composition

The term “particulate” as used herein means forms such as powders,granules, particles, flakes and other similar particulate forms that arecapable of being compacted into a more dense non-particulate form.

In particular for laundry tablets, detergent particles havingingredients such as builder and surfactant can be spray-dried in aconventional manner and then compacted at a suitable pressure. Thesurfactants and builders normally provide a substantial part of thecleaning power of the tablet. The term “builder” is intended to mean allmaterials which tend to remove calcium ion from solution, either by ionexchange, complexation, sequestration or precipitation.

The particulate material used for making the detergent tablet providedin this invention can be made by any particulation or granulationprocess. An example of such a process is spray drying (in a co-currentor counter current spray drying tower) which typically gives“spray-dried” detergent granules having low bulk densities of 600 g/l orlower. Particulate materials of higher density can be prepared bygranulation and densification in a high shear batch mixer/granulator orby a continuous granulation and densification process (e.g. usingLodige® CB and/or Lodige® KM mixers). Other suitable processes includefluid bed processes, compaction processes (e.g. roll compaction),extrusion, as well as any particulate material made by any chemicalprocess like flocculation, crystallization sentering, etc. Theindividual particles can also be in any other form, such as for example,particle, granule, sphere or grain.

The particulate materials may be mixed together by any conventionalmeans, for example, a concrete mixer, Nauta mixer, ribbon mixer or anyother. Alternatively the mixing process may be carried out continuouslyby metering each component by weight on to a moving belt, and blendingthem in one or more drum(s) or mixer(s). A liquid spray-on to the mix ofparticulate materials (e.g. non-ionic surfactants) may be carried out.Other liquid ingredients may also be sprayed on to the mix ofparticulate materials either separately or premixed. For example perfumeand slurries of optical brighteners may be sprayed. A finely dividedflow aid (dusting agent such as zeolites, carbonates, silicas) can beadded to the particulate materials after spraying the non-ionic,preferably towards the end of the process, to make the mix less sticky.

The detergent particles can be made by an agglomerate process comprisingthe steps of:

i) admixing one or more detergent surfactants, a perborate component andan acid source and optionally other detergent ingredients to form amixture; and

ii) agglomerating the mixture to form agglomerated particles or“agglomerates”.

Typically, such an agglomeration process involves mixing an effectiveamount of powder, including the acid source, with a high activesurfactant paste in one or more agglomerators such as a panagglomerator, a Z-blade mixer or more preferably in-line mixers,preferably two, such as those manufactured by Schugi (Holland) BV, 29Chroomstraat 8211 AS, Lelystad, Netherlands, and Gebruder LodigeMaschinenbau GmbH, D-4790 Paderborn 1, Elsenerstrasse 7-9, Postfach2050, Germany. Preferably a high shear mixer is used, such as a LodigeCB (Trade Name). Most preferably, a high shear mixer is used incombination with a low shear mixer, such as a Lodige CB (Trade Name) anda Lodige KM (Trade name) or Schugi KM (Trade Name). Optionally, only oneor more low shear mixer arc used. Preferably, the agglomerates arethereafter dried and/or cooled.

Another agglomeration process involves mixing of various components ofthe final agglomorate in different stages, using an fluidized bed. Forexample, a preferred particulate detergent in accordance with thepresent invention can be agglomerated by addition, preferably byspraying on, of nonionic, anionic surfactants and optionally a wax, ormixtures thereof, to the acid source in powdered form and other optionalingredients. Then, additional components, including the perborate bleachand optinally the alkali source or part thereof, can be added andagglomerated in one or more stages, thus forming the final agglomerateparticle.

The agglomerates may take the form of flakes, prills, marumes, noodles,ribbons, but preferably take the form of granules. A preferred way toprocess the particles is by agglomerating powders (e.g. aluminosilicate,carbonate) with high active surfactant pastes and to control theparticle size of the resulting agglomerates within specified limits.Typical particle sizes are from 0.10 mm to 5.0 mm in diameter,preferably from 0.25 mm to 3.0 mm in diameter, most preferably from 0.40mm to 1.00 mm in diameter. Typically, the “agglomerates” have a bulkdensity desirably ,of at least 700 g/l and preferably, in a range offrom about 700 g/l to about 900 g/l.

A high active surfactant paste comprising a mix of, typically, from 50%by weight to 95% by weight, preferably 70% by weight to 85% by weight ofsurfactant, and optionally it can contain an appropriate acid source.The paste may be pumped into the agglomerator at a temperature highenough to maintain a pumpable viscosity, but low enough to avoiddegradation of the anionic surfactants used. An operating temperature ofthe paste of 50° C. to 80° C. is typical. Such pastes and methods formaking and processing such pastes is for example described in WO93/03128. In the present invention, the detergent particles made byagglomeration process have a bulk density of greater than about 600 g/land the detergent is in the form of powder or a granulate.

Dry Detergent Material

The starting dry detergent material for making detergent tablets tocarry out the present invention, comprises materials selected from thegroup consisting of carbonates, sulfates, carbonate/sulfate complexes,tripolyphosphates, tetrasodium pyrophosphate, citrates,aluminosilicates, cellulose-based materials and organic syntheticpolymeric absorbent gelling materials. More preferably, the drydetergent material is selected from the group consisting ofaluminosilicate, carbonates, sulfates, carbonate/sulfate complexes, andmixtures thereof. Most preferably, the dry detergent material comprise adetergent aluminosilicate builder which are referenced asaluminosilicate ion exchange materials and sodium carbonate.

The aluminosilicate ion exchange materials used herein as a detergentbuilder preferably have both a high calcium ion exchange capacity and ahigh exchange rate. Without intending to be limited by theory, it isbelieved that such high calcium ion exchange rate and capacity are afunction of several interrelated factors which derive from the method bywhich the aluminosilicate ion exchange material is produced. In thatregard, the aluminosilicate ion exchange materials used herein arepreferably produced in accordance with Corkill et al, U.S. Pat. No.4,605,509 (Procter & Gamble), the disclosure of which is incorporatedherein by reference.

Preferably, the aluminosilicate ion exchange material is in “sodium”form since the potassium and hydrogen forms of the instantaluminosilicate do not exhibit the as high of an exchange rate andcapacity as provided by the sodium form. Additionally, thealuminosilicate ion exchange material preferably is in over dried formso as to facilitate production of crisp detergent agglomerates asdescribed herein. The aluminosilicate ion exchange materials used hereinpreferably have particle size diameters which optimize theireffectiveness as detergent builders. The term “particle size diameter”as used herein represents the average particle size diameter of a givenaluminosilicate ion exchange material as determined by conventionalanalytical techniques, such as microscopic determination and scanningelectron microscope (SEM). The preferred particle size diameter of thealuminosilicate is from about 0.1 micron to about 10 microns, morepreferably from about 0.5 microns to about 9 microns. Most preferably,the particle size diameter is from about 1 microns to about 8 microns.

Preferably, the aluminosilicate ion exchange material has the formula

Na_(z)[(AlO₂)_(z).(SiO₂)_(y)]xH₂O

wherein z and y are integers of at least 6, the molar ratio of z to y isfrom about 1 to about 5 and x is from about 10 to about 264. Morepreferably, the aluminosilicate has the formula

Na₁₂[(AlO₂)₁₂.(SiO₂)₁₂]xH₂O

wherein x is from about 20 to about 30, preferably about 27. Thesepreferred aluminosilicates are available commercially, for example underdesignations Zeolite A, Zeolite B and Zeolite X. Alternatively,naturally-occurring or synthetically derived aluminosilicate ionexchange materials suitable for use herein can be made as described inKrummel et al, U.S. Pat. No. 3,985,669, the disclosure of which isincorporated herein by reference.

The aluminosilicates used herein are further characterized by their ionexchange capacity which is at least about 200 mg equivalent of CaCO₃hardness/gram, calculated on an anhydrous basis, and which is preferablyin a range from about 300 to 352 mg equivalent of CaCO₃ hardness/gram.Additionally, the instant aluminosilicate ion exchange materials arestill further characterized by their calcium ion exchange rate which isat least about 2 grains Ca⁺⁺/gallon/minute/−gram/gallon, and morepreferably in a range from about 2 grainsCa⁺⁺/gallon/minute/−gram/gallon to about 6 grainsCa⁺⁺/gallon/minute/−gram/gallon.

Additionally, those builder materials discussed previously as anoptional coating agent can be used herein. These particular buildermaterials have the formula (M_(x))_(i) Ca_(y) (CO₃)_(z) wherein x and iare integers from 1 to 15, y is an integer from 1 to 10, z is an integerfrom 2 to 25, M_(i) are cations, at least one of which is awater-soluble, and the equation Σ_(i =) ₁₋₁₅(x_(i) multiplied by thevalence of M_(i))+2y=2z is satisfied such that the formula has a neutralor “balanced” charge. Additional details and examples of these buildermaterials have been set forth previously and are incorporated herein byreference. Preferably, these builder materials are selected from thegroup consisting of Na₂Ca(CO₃)₂, K₂Ca(CO₃)₂, Na₂Ca₂(CO₃)₃, NaKCa(CO₃)₂,NaKCa₂(CO₃)₃, K₂Ca₂(CO₃)₃, and combinations thereof.

Adjunct Detergent Ingredients

The starting dry detergent material in the present process can includeadditional detergent ingredients and/or, any number of additionalingredients can be incorporated in the detergent composition duringsubsequent steps of the present process. These adjunct ingredientsinclude other detergency builders, bleaches, bleach activators, sudsboosters or suds suppressors, anti-tarnish and anticorrosion agents,soil suspending agents, soil release agents, germicides, pH adjustingagents, non-builder alkalinity sources, chelating agents, smectiteclays, enzymes, enzyme-stabilizing agents and perfumes. See U.S. Pat.No. 3,936,537, issued Feb. 3, 1976 to Baskerville, Jr. et al.,incorporated herein by reference.

Other builders can be generally selected from the various water-soluble,alkali metal, ammonium or substituted ammonium phosphates,polyphosphates, phosphonates, polyphosphonates, carbonates, borates,polyhydroxy sulfonates, polyacetates, carboxylates, andpolycarboxylates. Preferred are the alkali metal, specially sodium,salts of the above. Preferred for use herein are the phosphates,carbonates, C₁₀₋₁₈ fatty acids, polycarboxylates, and mixtures thereof.More referred are sodium tripolyphosphate, tetrasodium pyrophosphate,citrate, tartrate ono- and di-succinates, and mixtures thereof (seebelow).

In comparison with amorphous sodium silicates, crystalline layeredsodium silicates exhibit a clearly increased calcium and magnesium ionexchange capacity. In addition, the layered sodium silicates prefermagnesium ions over calcium ions, a feature necessary to insure thatsubstantially all of the “hardness” is removed from the wash water.These crystalline layered sodium silicates, however, are generally moreexpensive than amorphous silicates as well as other builders.Accordingly, in order to provide an economically feasible laundrydetergent, the proportion of crystalline layered sodium silicates usedmust be determined judiciously.

The crystalline layered sodium silicates suitable for use hereinpreferably have the formula

NaMSi_(x)O_(2x+1).yH₂O

wherein M is sodium or hydrogen, x is from about 1.9 to about 4 and y isfrom about 0 to about 20. More preferably, the crystalline layeredsodium silicate has the formula

NaMSi₂O₅.yH₂O

wherein M is sodium or hydrogen, and y is from about 0 to about 20.These and other crystalline layered sodium silicates are discussed inCorkill et al, U.S. Pat. No. 4,605,509, previously incorporated hereinby reference.

Specific examples of inorganic phosphate builders are sodium andpotassium tripolyphosphate, pyrophosphate, polymeric metaphosphatehaving a degree of polymerization of from about 6 to 21, andorthophosphates. Examples of polyphosphonate builders are the sodium andpotassium salts of ethylene diphosphonic acid, the sodium and potassiumsalts of ethane 1-hydroxy-1,1-diphosphonic acid and the sodium andpotassium salts of ethane, 1,1,2-triphosphonic acid. Other phosphorusbuilder compounds are disclosed in U.S. Pat. Nos. 3,159,581; 3,213,030;3,422,021; 3,422,137; 3,400,176 and 3,400,148, all of which areincorporated herein by reference.

Examples of nonphosphorus, inorganic builders are tetraboratedecahydrate and silicates having a weight ratio of SiO₂ to alkali metaloxide of from about 0.5 to about 4.0, preferably from about 1.0 to about2.4. Water-soluble, nonphosphorus organic builders useful herein includethe various alkali metal, ammonium and substituted ammoniumpolyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates.Examples of polyacetate and polycarboxylate builders are the sodium,potassium, lithium, ammonium and substituted ammonium salts of ethylenediamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid,mellitic acid, benzene polycarboxylic acids, and citric acid.

Polymeric polycarboxylate builders are set forth in U.S. Pat. No.3,308,067, Diehl, issued Mar. 7, 1967, the disclosure of which isincorporated herein by reference. Such materials include thewater-soluble salts of homo- and copolymers of aliphatic carboxylicacids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid,aconitic acid, citraconic acid and methylene malonic acid. Some of thesematerials are useful as the water-soluble anionic polymer as hereinafterdescribed, but only if in intimate admixture with the non-soap anionicsurfactant.

Other suitable polycarboxylates for use herein are the polyacetalcarboxylates described in U.S. Pat. No. 4,144,226, issued Mar. 13, 1979to Crutchfield et al, and U.S. Pat. No. 4,246,495, issued Mar. 27, 1979to Crutchfield et al, both of which are incorporated herein byreference. These polyacetal carboxylates can be prepared by bringingtogether under polymerization conditions an ester of glyoxylic acid anda polymerization initiator. The resulting polyacetal carboxylate esteris then attached to chemically stable end groups to stabilize thepolyacetal carboxylate against rapid depolymerization in alkalinesolution, converted to the corresponding salt, and added to a detergentcomposition. Particularly preferred polycarboxylate builders are theether carboxylate builder compositions comprising a combination oftartrate monosuccinate and tartrate disuccinate described in U.S. Pat.No. 4,663,071, Bush et al., issued May 5, 1987, the disclosure of whichis incorporated herein by reference.

Bleaching agents and activators are described in U.S. Pat. No.4,412,934, Chung et al., issued Nov. 1, 1983, and in U.S. Pat. No.4,483,781, Hartman, issued Nov. 20, 1984, both of which are incorporatedherein by reference. Chelating agents are also described in U.S. Pat.No. 4,663,071, Bush et al., from Column 17, line 54 through Column 18,line 68, incorporated herein by reference. Suds modifiers are alsooptional ingredients and are described in U.S. Pat. No. 3,933,672,issued Jan. 20, 1976 to Bartoletta et al., and U.S. Pat. No. 4,136,045,issued Jan. 23, 1979 to Gault et al., both incorporated herein byreference.

Suitable smectite clays for use herein are described in U.S. Pat. No.4,762,645, Tucker et al, issued Aug. 9, 1988, Column 6, line 3 throughColumn 7, line 24, incorporated herein by reference. Suitable additionaldetergency builders for use herein are enumerated in the Baskervillepatent, Column 13, line 54 through Column 16, line 16, and in U.S. Pat.No. 4,663,071, Bush et al, issued May 5, 1987, both incorporated hereinby reference.

The Non-particulate Detergent Product

The detergent tablets can be prepared simply by mixing the solidingredients together and compressing the mixture in a conventionaltablet press as used, for example, in the pharmaceutical industry.

The detergent tablets provided can be made in any size or shape. Priorto compaction, the detergent particles may be surface treated with aflow aid according to the present invention. The detergent tabletsprovided may be manufactured by using any compacting process, such astabletting, briquetting, or extrusion, preferably tabletting. Suitableequipment includes a standard single stroke or a rotary press (such asCourtoy®, Korch®, Manesty®, or Bonals®). As used herein, the term“non-particulate detergent product” includes physical shapes such astablets, blocks, bars and the like.

Detergent Core having Chamfered Edges

In the preferred embodiment of the present invention, the core iscompressed into a tubular configuration having a polygonal cross-sectionand a plurality of surfaces meeting to form a plurality of edges,thereby forming a contoured core, wherein at least one of the pluralityof edges is chamfered. The core, in alternate embodiments, has one ormore of a triangular, circular, or rectangular cross-sections. Variouscross-sections and shapes are envisioned to be within the scope of thepresent invention, such as tablets, bars and the like.

The chamfered edges can have a variety of shapes and geometricalconfigurations. In one embodiment, as shown in FIG. 1, the core has a 45degree chamfer. Various other angles are possible, ranging from 15degrees to 75 degrees. Multiple chamfer are also envisioned in otherembodiments of this invention. In one embodiment a plurality of chamfersare formed as shown in FIG. 2. Alternatively, the chamfer may be in theform of a radius as shown in FIG. 3. FIGS. 1, 2, and 3 each show adetergent core 10 covered by a coating 12. The coating 12 has achamfered edge 20. FIG. 2 shows the chamfer having two surfaces 22, 24.

Coating for Non-particulate Detergent Product

In the preferred embodiment, the non-particulate detergent productfurther includes a coating which substantially covers the contouredcore. Preferably, the coating mimics the surface contours of the core,thereby having an outer coating surface that has substantially similarsurface geometry as that of the core.

The coating is provided in order to provide mechanical strength andshock and chip resistance to the compressed tablet core. The tablets arecoated with a coating that is preferably substantially insoluble inwater so that the tablet does not absorb moisture, or absorbs moistureat only a very slow rate. The coating is strong so that moderatemechanical shocks to which the tablets are subjected during handling,packing and shipping result in no more than very low levels of breakageor attrition. Further, the coating is preferably brittle so that thetablet breaks up when subjected to stronger mechanical shock.Furthermore it is advantageous if the coating material is dissolvedunder alkaline conditions, or is readily emulsified by surfactants. Thisavoids the deposition of undissolved particles or lumps of coatingmaterial on the laundry load. This may be important when the coatingmaterial is completely insoluble (for example less than 1 g/l) in water.

As defined herein “substantially insoluble” means having a very lowsolubility in water. This should be understood to mean having asolubility in water at 25° C. of less than 20 g/L, preferably less than5 g/l, and more preferably less than 1 g/l. Water solubility is measuredfollowing the test protocol of ASTM E1148-87 entitled, “Standard TestMethod for Measurements of Aqueous Solubility”.

Suitable coating materials are fatty acids, adipic acid and C8-C13dicarboxylic acids, fatty alcohols, diols, esters and ethers. Preferredfatty acids are those having a carbon chain length of from C12 to C22and most preferably from C18 to C22. Preferred dicarboxylic acids areadipic acid (C6), suberic acid (C8), azelaic acid (C9), sebacic acid(C10), undecanedioic acid (C11), dodecanedioic acid (C12) andtridecanedioic acid (C13). Preferred fatty alcohols are those having acarbon chain length of from C12 to C22 and most preferably from C14 toC18.

Preferred diols are 1,2-octadecanediol and 1,2-hexadecanediol. Preferredesters are tristearin, tripalmitin, methylbehenate, ethylstearate.Preferred ethers are diethyleneglycol mono hexadecylether,diethyleneglycol mono octadecylether, diethyleneglycol monotetradecylether, phenylether, ethyl naphtyl ether, 2 methoxynaphtalene,beta naphtyl methyl ether and glycerol monooctadecylether. Otherpreferred coating materials include dimethyl 2,2 propanol, 2hexadecanol, 2 octadecanone, 2 hexadecanone, 2, 15 hexadecanedione and 2hydroxybenzyl alcohol. The coating is a hydrophobic material having amelting point preferably of from 40° C. to 180° C.

In the preferred embodiment, the coating can be applied in a number ofways. Two preferred coating methods are a) coating with a moltenmaterial and b) coating with a solution of the material. In a), thecoating material is applied at a temperature above its melting point,and solidifies on the tablet. In b), the coating is applied as asolution, the solvent being dried to leave a coherent coating. Thesubstantially insoluble material can be applied to the tablet by, forexample, spraying or dipping. Normally when the molten material issprayed on to the tablet, it will rapidly solidify to form a coherentcoating. When tablets are dipped into the molten material and thenremoved, the rapid cooling again causes rapid solidification of thecoating material. Clearly substantially insoluble materials having amelting point below 40° C. are not sufficiently solid at ambienttemperatures and it has been found that materials having a melting pointabove about 180° C. are not practicable to use. Preferably, thematerials melt in the range from 60° C. to 160° C. , more preferablyfrom 70° C. to 120° C.

By “melting point” is meant the temperature at which the material whenheated slowly in, for example, a capillary tube becomes a clear liquid.For most purposes, the coating forms from 1% to 10%, preferably from1.5% to 5%, of the tablet weight.

Compaction of Particulate Detergent to Form Non-particulate DetergentProduct

In the preferred embodiment, the chip resistant detergent product has acore formed by compacting the particulate detergent composition byapplying a pressure in an amount sufficient to form a non-particulatedetergent product having a density of at least about 1000 g/l. It isdesirable to form a detergent tablet that has a density of at leastabout 1000 g/l so that the tablet will sink in water. If the density ofthe detergent tablet is less than about 1000 g/l, the tablet will floatwhen placed in the water in a washing machine and this willdetrimentally reduce the dissolution rate of the tablet in the water. Itis desirable to apply at least that much pressure as is sufficient tocompress the particulate detergent material to form a tablet having adensity of at least about 1000 g/l.

EXAMPLE A

Detergent tablets are formed according to the following composition:

TABLE A.1 Particulate detergent Ingredients % by weight C₁₂₋₁₆ linearalkylbenzene sulfonate 8.80 C₁₄₋₁₅ alkyl sulfate/C₁₄₋₁₅ alkyl ethoxysulfate 8.31 C₁₂₋₁₃ alkyl ethoxylate 1.76 polyacrylate (MW = 4500) 2.40polyethylene glycol (MW = 4000) 0.96 sodium sulfate 8.40 aluminosilicate21.28 sodium carbonate 16.80 protease enzyme 0.32 sodium perboratemonohydrate 2.08 lipase enzyme 0.17 cellulase enzyme 0.08 NOBS extrudate4.80 citric acid monohydrate 2.25 sodium bicarbonate 2.75 sodium acetate15.00 free water 1.60 other minor ingredients (perfume etc.) 2.24 Total100.00

The detergent tablet formed is coated with a coating according to thefollowing composition:

TABLE A.3 Ingredient % by weight Detergent core 91.10 Coating:dodecanedioc acid 8.00 carboxymethyl cellulose 0.90 Total 100.00

The tablets are formed by compressing the tablet ingredients in acylindrical die having a diameter of 55 mm using a laboratory presshaving a trade name Carver Model 3912, to form a tablet having a heightof 20 mm. The formed tablets are then coated with the protective coatingby dipping the tablet into a molten bath of the coating for about 3seconds. The molten coating bath is maintained at a temperature of about145 degrees centigrade.

The term “NOBS extrudate” as used herein, is an acronym for the chemicalsodium nonanoyloxybenzene sulfonate, commercially available from EastmanChemicals, Inc. The carboxymethyl cellulose used in the above example iscommercially available from Metsa-Serla and sold under the trade name,Nymcel ZSB-16.

Accordingly, having thus described the invention in detail, it will beobvious to those skilled in the art that various changes may be madewithout departing from the scope of the invention and the invention isnot to be considered limited to what is described in the specification.

What is claimed is:
 1. A non-particulate laundry and/or automaticdishwashing detergent product, comprising: a core formed by compressinga particulate material, wherein the particulate material comprises adetersive surfactant and a builder; said core having a tubularconfiguration having a polygonal cross-section and a plurality ofsurfaces meeting to form a plurality of edges, thereby forming acontoured core, wherein at least one of said plurality of edges ischamfered; and wherein the contoured core is substantially covered by acoating.
 2. The non-particulate detergent of claim 1 wherein saidcoating covers said contoured core.
 3. The non-particulate detergent ofclaim 1 wherein said core has a rectangular cross section.
 4. Thenon-particulate detergent of claim 1 wherein said core has a triangularcross section.
 5. The non-particulate detergent of claim 2 wherein saidcoating comprises dicarboxylic acid.
 6. The non-particulate detergentproduct of claim 1 wherein said coating is insoluble in water.
 7. Thenon-particulate detergent product of claim 1 wherein said coatingcomprises dicarboxylic acid.
 8. The non-particulate detergent product ofclaim 1 wherein said coating comprises a material which is insoluble inwater at 25 degrees C.
 9. The non-particulate detergent product of claim1 wherein said coating comprises a water-insoluble material having amelting point in the range of about 40 degrees C to about 180 degrees C.10. The non-particulate detergent product of claim 1 wherein saidcoating is selected from the group of materials consisting of C12-C22fatty acids, adipic acid, C8-C13 dicarboxylic acids, or mixturesthereof.
 11. The non-particulate detergent product of claim 1 whereinsaid coating is selected from the group of materials consisting ofC12-C22 fatty alcohols.
 12. The non-particulate detergent product ofclaim 1 wherein said core has s density of at least 1000 g/l.
 13. Thenon-particulate detergent product of claim 1 wherein said chamfer is a45 degree chamfer.
 14. The non-particulate detergent product of claim 1wherein said chamfer has an angle in a range of from about 15 degrees toabout 75 degrees.
 15. The non-particulate detergent product of claim 1wherein said chamfer is a radiused chamfer.
 16. The non-particulatedetergent product of claim 1 wherein said chamfer comprises a pluralityof surfaces.